348 FOUNDATIONS OF BOTANY 
same region can hardly be distinguished from the earth in 
which they grow. 
416. Plants of Uneatable Texture. — Whenever tender 
and juicy herbage is to be had, plants of bard and stringy 
texture are left untouched. ‘The flinty-stemmed scouring- 
rushes (Hquisetum, Sect. 361) and the dry, tough rushes 
are familiar examples of uneatable plants of damp soil. 
In pastures there grow such peren- 
nials as the bracken fern and the 
hardhack of New England and the 
ironweed and vervains of the Cen- 
tral States, which are so harsh and 
woody that the hungriest browsing 
Fic. 243.— Spiny Leaves of Barberry. 
animal is rarely, if ever, seen to molest them. Still other 
plants, like the knotgrass and cinquefoil of our dooryards, 
are doubly safe, from their growing so close to the ground 
as to be hard to graze and from their woody and unpala- 
table nature. The date-palm (which can easily be raised 
from the seed in the schoolroom or the laboratory) is an 
excellent instance of the same uneatable quality, found 
in a tropical or sub-tropical plant. 
